The present invention relates generally to the field of power conversion systems such as those used convert direct current (DC) power to alternating current (AC) power. More particularly, the present invention relates to systems and methods for using pulse width modulation (PWM) techniques capable of high speed switching of electrical energy to drive power electronic devices, such as insulated gate bipolar transistors (IGBTs).
Electric drives are used in a wide range of applications. For example, drives incorporating power electronic switching circuits are used to power AC motors capable of converting electrical energy for use with centrifuges, magnetic clutches, pumps and more generally, in electric motor drive controllers that transform and condition incoming AC power for supply to motor drive circuitry. In certain motor drive circuits, PWM is utilized to redirect and rectify incoming AC power and to deliver variable DC or AC power, as well as in DC/AC and AC/AC conversion. Accordingly, PWM techniques may be used to switch the IGBTs on and off according to different phases of the incoming AC power. However, one drawback of PWM drives is that they may experience high common-mode voltages.